SUBELEMENT T4 – AMATEUR RADIO PRACTICES

Question 1

Which of the following is an appropriate power supply rating for a typical 50 watt output mobile FM transceiver? T4A01
A. 24.0 volts at 4 amperes
B. 13.8 volts at 4 amperes
C. 24.0 volts at 12 amperes
D. 13.8 volts at 12 amperes

Answer 1

D. 13.8 volts at 12 amperes

Question 2

Which of the following should be considered when selecting an accessory SWR meter? T4A02
A. The frequency and power level at which the measurements will be made
B. The distance that the meter will be located from the antenna
C. The types of modulation being used at the station
D. All these choices are correct

Answer 2

A. The frequency and power level at which the measurements will be made

Question 3

Why are short, heavy-gauge wires used for a transceiver’s DC power connection? T4A03
A. To minimize voltage drop when transmitting
B. To provide a good counterpoise for the antenna
C. To avoid RF interference
D. All these choices are correct

Answer 3

A. To minimize voltage drop when transmitting

Question 4

How are the transceiver audio input and output connected in a station configured to operate using FT8? T4A04
A. To a computer running a terminal program and connected to a terminal node controller unit
B. To the audio input and output of a computer running WSJT-X software
C. To an FT8 conversion unit, a keyboard, and a computer monitor
D. To a computer connected to the FT8converter.com website

Answer 4

B. To the audio input and output of a computer running WSJT-X software

Question 5

Where should an RF power meter be installed? T4A05
A. In the feed line, between the transmitter and antenna
B. At the power supply output
C. In parallel with the push-to-talk line and the antenna
D. In the power supply cable, as close as possible to the radio

Answer 5

A. In the feed line, between the transmitter and antenna

Question 6

What signals are used in a computer-radio interface for digital mode operation? T4A06
A. Receive and transmit mode, status, and location
B. Antenna and RF power
C. Receive audio, transmit audio, and transmitter keying
D. NMEA GPS location and DC power

Answer 6

C. Receive audio, transmit audio, and transmitter keying

Question 7

Which of the following connections is made between a computer and a transceiver to use computer software when operating digital modes? T4A07
A. Computer “line out” to transceiver push-to-talk
B. Computer “line in” to transceiver push-to-talk
C. Computer “line in” to transceiver speaker connector
D. Computer “line out” to transceiver speaker connector

Answer 7

C. Computer “line in” to transceiver speaker connector

Question 8

Which of the following conductors is preferred for bonding at RF? T4A08
A. Copper braid removed from coaxial cable
B. Steel wire
C. Twisted-pair cable
D. Flat copper strap

Answer 8

D. Flat copper strap

Question 9

How can you determine the length of time that equipment can be powered from a battery? T4A09
A. Divide the watt-hour rating of the battery by the peak power consumption of the equipment
B. Divide the battery ampere-hour rating by the average current draw of the equipment
C. Multiply the watts per hour consumed by the equipment by the battery power rating
D. Multiply the square of the current rating of the battery by the input resistance of the equipment

Answer 9

B. Divide the battery ampere-hour rating by the average current draw of the equipment

Question 10

What function is performed with a transceiver and a digital mode hot spot? T4A10
A. Communication using digital voice or data systems via the internet
B. FT8 digital communications via AFSK
C. RTTY encoding and decoding without a computer
D. High-speed digital communications for meteor scatter

Answer 10

A. Communication using digital voice or data systems via the internet

Question 11

Where should the negative power return of a mobile transceiver be connected in a vehicle? T4A11
A. At the 12 volt battery chassis ground
B. At the antenna mount
C. To any metal part of the vehicle
D. Through the transceiver’s mounting bracket

Answer 11

A. At the 12 volt battery chassis ground

Question 12

What is an electronic keyer? T4A12
A. A device for switching antennas from transmit to receive
B. A device for voice activated switching from receive to transmit
C. A device that assists in manual sending of Morse code
D. An interlock to prevent unauthorized use of a radio

Answer 12

C. A device that assists in manual sending of Morse code

Question 13

What is the effect of excessive microphone gain on SSB transmissions? T4B01
A. Frequency instability
B. Distorted transmitted audio
C. Increased SWR
D. All these choices are correct

Answer 13

B. Distorted transmitted audio

Question 14

Which of the following can be used to enter a transceiver’s operating frequency? T4B02
A. The keypad or VFO knob
B. The CTCSS or DTMF encoder
C. The Automatic Frequency Control
D. All these choices are correct

Answer 14

A. The keypad or VFO knob

Question 15

How is squelch adjusted so that a weak FM signal can be heard? T4B03
A. Set the squelch threshold so that receiver output audio is on all the time
B. Turn up the audio level until it overcomes the squelch threshold
C. Turn on the anti-squelch function
D. Enable squelch enhancement

Answer 15

A. Set the squelch threshold so that receiver output audio is on all the time

Question 16

What is a way to enable quick access to a favorite frequency or channel on your transceiver? T4B04
A. Enable the frequency offset
B. Store it in a memory channel
C. Enable the VOX
D. Use the scan mode to select the desired frequency

Answer 16

B. Store it in a memory channel

Question 17

What does the scanning function of an FM transceiver do? T4B05
A. Checks incoming signal deviation
B. Prevents interference to nearby repeaters
C. Tunes through a range of frequencies to check for activity
D. Checks for messages left on a digital bulletin board

Answer 17

C. Tunes through a range of frequencies to check for activity

Question 18

Which of the following controls could be used if the voice pitch of a single-sideband signal returning to your CQ call seems too high or low? T4B06
A. The AGC or limiter
B. The bandwidth selection
C. The tone squelch
D. The RIT or Clarifier

Answer 18

D. The RIT or Clarifier

Question 19

What does a DMR “code plug” contain? T4B07
A. Your call sign in CW for automatic identification
B. Access information for repeaters and talkgroups
C. The codec for digitizing audio
D. The DMR software version

Answer 19

B. Access information for repeaters and talkgroups

Question 20

What is the advantage of having multiple receive bandwidth choices on a multimode transceiver? T4B08
A. Permits monitoring several modes at once by selecting a separate filter for each mode
B. Permits noise or interference reduction by selecting a bandwidth matching the mode
C. Increases the number of frequencies that can be stored in memory
D. Increases the amount of offset between receive and transmit frequencies

Answer 20

B. Permits noise or interference reduction by selecting a bandwidth matching the mode

Question 21

How is a specific group of stations selected on a digital voice transceiver? T4B09
A. By retrieving the frequencies from transceiver memory
B. By enabling the group’s CTCSS tone
C. By entering the group’s identification code
D. By activating automatic identification

Answer 21

C. By entering the group’s identification code

Question 22

Which of the following receiver filter bandwidths provides the best signal-to-noise ratio for SSB reception? T4B10
A. 500 Hz
B. 1000 Hz
C. 2400 Hz
D. 5000 Hz

Answer 22

C. 2400 Hz

Question 23

Which of the following must be programmed into a D-STAR digital transceiver before transmitting? T4B11
A. Your call sign
B. Your output power
C. The codec type being used
D. All these choices are correct

Answer 23

A. Your call sign

Question 24

What is the result of tuning an FM receiver above or below a signal’s frequency? T4B12
A. Change in audio pitch
B. Sideband inversion
C. Generation of a heterodyne tone
D. Distortion of the signal’s audio

Answer 24

D. Distortion of the signal’s audio